S R Rayhan
S R Rayhan — Software Engineer

Turning Coffee
Into Code

Associate Software Engineer @ ShellBeeHaken Ltd | Software Engineering @ SUST | Full Stack Developer | Creative Coder | Passionate Learner

About me

I'm Rayhan — an Associate Software Engineer at Shellbeehaken Ltd and a BSc Software Engineering student at Shahjalal University of Science and Technology (CGPA: 3.57/4). I build across the full stack: from React frontends to Nest.js backends, game engines to distributed systems.

Outside of work, I solve problems — 600+ and counting on Codeforces, Codechef, and Leetcode. I also write technical articles on topics like Bloom Filters and distributed locking. I believe software should be fast, readable, and built to last.

>C/C++
>Java
>JavaScript
>TypeScript
>React.js
>Next.js
>Nest.js
>Node.js
>MySQL
>MongoDB
>Redis
>Tailwind CSS
>Git
>GitHub

Where I've worked

Associate Software Engineer

@ Shellbeehaken Ltd
June 2025 – Present
  • –Developed and contributed to a live project, Kriyakarak, delivering end-to-end functionality.
  • –Designed and implemented multiple backend services and frontend interfaces, enhancing system usability.
  • –Familiar with concepts including clustering, rate limiting, caching, and multi-instance data synchronization.
Next.jsReact.jsNode.jsRedisMongoDB

Intern Software Engineer

@ Shellbeehaken Ltd
December 2024 – May 2025
  • –Built a Snake & Ladders game with React.js, deepening understanding of components and state management.
  • –Built a Twitter clone with Next.js, exploring full-stack development and server-side rendering.
  • –Learned Git & GitHub to manage version control and collaborate on projects smoothly.
  • –Created a dice-based game using JavaScript to apply core programming concepts.
React.jsNext.jsJavaScriptGitHTML/CSS

Things I've built

Twitter Clone

Feb 2025 – Mar 2025

A full-stack social media application with posting, likes, retweets, replies, follow system, and real-time notifications. Secure authentication via Auth.js (JWT & OAuth) with RESTful APIs.

Next.jsMongoDBWebSocketsAuth.jsTypeScript

Eco-Sync

Apr 2024 – May 2024

A full-stack web application for DNCC's waste management system. Features task assignment, role management, and billing workflows with a responsive, user-friendly interface.

React.jsNode.jsMySQLREST API

SUST Football Tournament

Mar 2024 – Apr 2024

A web application to manage match schedules, player profiles, manager information, and tournament data. Includes JWT-based authentication and middleware for route protection.

React.jsNode.jsMySQLJWT

Link's Adventure: A Lone Warrior

Apr 2022 – May 2022

A 2D action game where the player saves the princess by defeating enemies and collecting keys. Implements movement mechanics, combat action logic, and custom game graphics.

JavaLibGDX

Turning Thoughts Into Articles

Speed Up Username Availability Checks Using Bloom Filter

Explaining how to use Bloom Filters to optimize high-frequency check operations in web applications.

Lock It Down: A Practical Guide to Distributed Locking

A deep dive into managing resource consistency across distributed systems using locking patterns.

Find the Set of X Satifying Mathematical Equations

Solving complex mathematical constraints through programmatic logic and optimization.

Get in touch

Whether it's a new project, a collaboration, or just a chat about code — my inbox is always open. I'll get back to you as soon as I can.